The present invention relates to a new and improved construction of positioning device for a mechanical switching lever arrangement, especially at an embroidery machine, and to a method of using such positioning device.
In many technological fields of application it is necessary to automatically displace switching lever arrangements for instance according to a selectable program. For this purpose, it is beneficial to use electromagnets as the positioning or adjustment means. However, if the switching lever arrangements to be displaced are voluminous and/or if the displacement paths are relatively long, then there are required comparatively large powerful electromagnets for carrying out the necessary positioning or adjustment work.
For instance, at embroidery machines it is necessary, among other things, to selectively bring the embroidering implements arranged at the embroidery locations into an effectual, i.e. working position, and into an ineffectual, i.e. rest position. For this purpose, the positioning or adjustment means are actuated, for instance, by electromagnets. At an embroidery machine, where 1000 or more such embroidery locations to be adjusted or displaced may be present, the power consumption at the positioning electromagnets is of considerable importance. A further drawback is the great structural volume of such arrangements.